Spot color
Encyclopedia
In offset printing
, a spot color is any color generated by an ink
(pure or mixed) that is printed using a single run.
The widely spread offset-printing process is composed of four spot colors: Cyan
, Magenta
, Yellow
, and Key
(black
) commonly referred to as CMYK. More advanced processes involve the use of six spot colors (hexachromatic process
), which add Orange
and Green
to the process (termed CMYKOG). The two additional spot colors are added to compensate for the ineffective reproduction of faint tints
using CMYK colors only. However, offset technicians around the world use the term spot color to mean any color generated by a non-standard offset ink; such as metallic, fluorescent, spot varnish, or custom hand-mixed inks.
When making a multi-color print with a spot color process, every spot color needs its own lithographic film. All the areas of the same spot color are printed using the same film, hence, using the same lithographic plate. The dot gain
, hence the screen angle
and line frequency, of a spot color vary according to its intended purpose. Spot lamination and UV coatings are sometimes referred to as 'spot colors', as they share the characteristics of requiring a separate lithographic film and print run.
artwork. Software applications such as Adobe InDesign
, Adobe Illustrator
, CorelDRAW
, QuarkXPress
and Scribus
may generate spot colors as additional channels. Adobe Photoshop
can also be used to generate soft edges (widely known as feathered edges) of spot colors. The dissolve effect provided by Adobe Photoshop layer patterns can be generated for any spot color.
, passport
s, bonds, and other similar prints that should be hard to forge. Money printing for example, uses secret formulae of spot colors, some of which can be seen by the naked eye, and some cannot be seen unless by using special lights, or by applying certain chemicals.
should be done to realize a good balance between reproduction of gray color on paper and on screen.
Because each color system creates their own colors from scratch, spot colors from one system may be impossible to find within the library of another.
Offset printing
Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface...
, a spot color is any color generated by an ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...
(pure or mixed) that is printed using a single run.
The widely spread offset-printing process is composed of four spot colors: Cyan
Cyan
Cyan from , transliterated: kýanos, meaning "dark blue substance") may be used as the name of any of a number of colors in the blue/green range of the spectrum. In reference to the visible spectrum cyan is used to refer to the color obtained by mixing equal amounts of green and blue light or the...
, Magenta
Magenta
Magenta is a color evoked by light stronger in blue and red wavelengths than in yellowish-green wavelengths . In light experiments, magenta can be produced by removing the lime-green wavelengths from white light...
, Yellow
Yellow
Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...
, and Key
Keyline
A keyline, in graphic design, is a boundary line that separates color and monochromatic areas or differently colored areas of printing on a given page or other printed piece. The line itself, usually consisting of a black border, provides an area in which lighter colors can be printed with slight...
(black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
) commonly referred to as CMYK. More advanced processes involve the use of six spot colors (hexachromatic process
Hexachrome
Hexachrome was a six-color printing process designed by Pantone Inc. In addition to custom CMYK inks, Hexachrome added orange and green inks to expand the color gamut, for better color reproduction. It was therefore also known as a CMYKOG process....
), which add Orange
Orange (colour)
The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nm, and has a hue of 30° in HSV colour space. It is numerically halfway between red and yellow in a gamma-compressed RGB colour space, the expression of which is the RGB colour wheel. The...
and Green
Green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
to the process (termed CMYKOG). The two additional spot colors are added to compensate for the ineffective reproduction of faint tints
Tints and shades
In color theory, a tint is the mixture of a color with white, which increases lightness, and a shade is the mixture of a color with black, which reduces lightness...
using CMYK colors only. However, offset technicians around the world use the term spot color to mean any color generated by a non-standard offset ink; such as metallic, fluorescent, spot varnish, or custom hand-mixed inks.
When making a multi-color print with a spot color process, every spot color needs its own lithographic film. All the areas of the same spot color are printed using the same film, hence, using the same lithographic plate. The dot gain
Dot gain
Dot gain is a phenomenon in offset lithography and some other forms of printing which causes printed material to look darker than intended. It is caused by halftone dots growing in area between the original printing film and the final printed result...
, hence the screen angle
Screen angle
In offset printing, the screen angle is the angle at which the halftones of a separated color is outputted to a lithographic film, hence, printed on final product media.-Why should screen angles differ:...
and line frequency, of a spot color vary according to its intended purpose. Spot lamination and UV coatings are sometimes referred to as 'spot colors', as they share the characteristics of requiring a separate lithographic film and print run.
Computer methods
There are various methods to incorporate rather sophisticated patterns of spot colors in the final prepressPrepress
Prepress is the term used in the printing and publishing industries for the processes and procedures that occur between the creation of a print layout and the final printing...
artwork. Software applications such as Adobe InDesign
Adobe InDesign
Adobe InDesign is a software application produced by Adobe Systems. It can be used to create works such as posters, flyers, brochures, magazines, newspapers and books. In conjunction with Adobe Digital Publishing Suite InDesign can publish content suitable for tablet devices...
, Adobe Illustrator
Adobe Illustrator
Adobe Illustrator is a vector graphics editor developed and marketed by Adobe Systems. Illustrator is similar in scope, intended market, and functionality to its competitors, CorelDraw, Xara Designer Pro and Macromedia FreeHand....
, CorelDRAW
CorelDRAW
CorelDRAW is a vector graphics editor developed and marketed by Corel Corporation of Ottawa, Canada. It is also the name of Corel's Graphics Suite...
, QuarkXPress
QuarkXPress
QuarkXPress is a computer application for creating and editing complex page layouts in a WYSIWYG environment. It runs on Mac OS X and Windows. It was first released by Quark, Inc...
and Scribus
Scribus
Scribus is a desktop publishing application, released under the GNU General Public License as free software. It is based on the free Qt toolkit, therefore native versions are available for Linux, Unix-like operating systems, Mac OS X, Microsoft Windows, and OS/2...
may generate spot colors as additional channels. Adobe Photoshop
Adobe Photoshop
Adobe Photoshop is a graphics editing program developed and published by Adobe Systems Incorporated.Adobe's 2003 "Creative Suite" rebranding led to Adobe Photoshop 8's renaming to Adobe Photoshop CS. Thus, Adobe Photoshop CS5 is the 12th major release of Adobe Photoshop...
can also be used to generate soft edges (widely known as feathered edges) of spot colors. The dissolve effect provided by Adobe Photoshop layer patterns can be generated for any spot color.
Optimizing usage
Generally the cost and potential for problems for a print job increase as one adds more spot colors, due to the increased cost and complexity of added process inks and films, and requiring more runs per finished print. However, spot colors can be a very powerful weapon in security printing, like moneyMoney
Money is any object or record that is generally accepted as payment for goods and services and repayment of debts in a given country or socio-economic context. The main functions of money are distinguished as: a medium of exchange; a unit of account; a store of value; and, occasionally in the past,...
, passport
Passport
A passport is a document, issued by a national government, which certifies, for the purpose of international travel, the identity and nationality of its holder. The elements of identity are name, date of birth, sex, and place of birth....
s, bonds, and other similar prints that should be hard to forge. Money printing for example, uses secret formulae of spot colors, some of which can be seen by the naked eye, and some cannot be seen unless by using special lights, or by applying certain chemicals.
Digitization
Spot colors are now a great business for a company like Pantone. The modern trend in spot color matching systems is the digitization of spot colors. This idea came from the fact that a spot color print won't be a match to the monitor's colors, due to the inherent differences in printed (ink) colors and monitor (light) colors. To achieve a rather good result of simulating the RGB colors into CMYK colors in offset prints, a proper monitor calibrationColor calibration
The aim of color calibration is to measure and/or adjust the color response of a device to a known state. In ICC terms this is the basis for a additional color characterization of the device and later profiling. In non ICC workflows calibration refers sometimes to establishing a known relationship...
should be done to realize a good balance between reproduction of gray color on paper and on screen.
Classification
Spot color classification has led to thousands of discrete colors being given unique names or numbers. There are several industry standards in the classification of spot color systems, such as:- PantonePantonePantone Inc. is a corporation headquartered in Carlstadt, New Jersey, USA. The company is best known for its Pantone Matching System , a proprietary color space...
, the dominant spot color printing system in the United StatesUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
and EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. - Toyo, a common spot color system in JapanJapanJapan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. - DIC, another common Japanese spot color system.
- ANPANewspaper Association of AmericaThe Newspaper Association of America is a trade association representing approximately 2000 newspapers in the United States and Canada. Member newspapers represented by the NAA include large daily papers, non-daily and small-market publications, as well as digital and multiplatform...
, a palette of 300 colors specified by the American Newspaper Publishers AssociationNewspaper Association of AmericaThe Newspaper Association of America is a trade association representing approximately 2000 newspapers in the United States and Canada. Member newspapers represented by the NAA include large daily papers, non-daily and small-market publications, as well as digital and multiplatform...
for spot color usage in newspapers. - GCMI, a standard for color used in package printing developed by the Glass Packaging Institute (formerly known as the Glass Container Manufacturers Institute, hence the abbreviation).
- HKSHKS (colour system)The HKS is a colour system which contains 120 spot colours and 3250 tones for coated and uncoated paper. HKS is an abbreviation of three German colour manufacturers: Hostmann-Steinberg Druckfarben, Kast + Ehinger Druckfarben, and H. Schmincke & Co....
is a color system which contains 120 spot colors and 3250 tones for coated and uncoated paper. HKS is an abbreviation of three German color manufacturers: Hostmann-Steinberg Druckfarben, Kast + Ehinger Druckfarben and H. Schmincke & Co.
Because each color system creates their own colors from scratch, spot colors from one system may be impossible to find within the library of another.
See also
- CMYK color space and printing (also called process color)
- colorColorColor or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
- color printingColor printingColor printing or Colour printing is the reproduction of an image or text in color...
- four-color printing
- printingPrintingPrinting is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
- Spreading and chokingSpreading and chokingTrapping is a term most commonly used in the prepress industry to describe the compensation for misregistration between printing units on a multicolor press. This misregistration causes unsightly gaps or white-space on the final printed work...